Maybe it's about his grandfather, I know Ace lost him right at the end of TEN's last tour, amidst the break-up of the band and everything maybe his life was hectic and he may have skipped out on talking or visiting his grandfather, and then he passed away before Ace got another chance to talk to him. This song seems to be about regret, so maybe it's regret for not getting to say goodbye to him. This is just a guess.
Maybe it's about his grandfather, I know Ace lost him right at the end of TEN's last tour, amidst the break-up of the band and everything maybe his life was hectic and he may have skipped out on talking or visiting his grandfather, and then he passed away before Ace got another chance to talk to him. This song seems to be about regret, so maybe it's regret for not getting to say goodbye to him. This is just a guess.